An electrical insulator acts as a barrier between the electricity flowing in a charged electrical utility line and the ground. For brevity, the term “electrical wire” or, for brevity, “wire” (including plural forms), is used herein to encompass various conduits through which electricity passes including wires, cables, and utility lines.
Conventionally, wires are attached to and supported by poles, towers, and other support structures by both an insulator and a clamping arrangement to secure the live line to the insulator. Typically, the clamping arrangement includes an insulator and a clamping device comprising a body member on which the line is placed and a clamping arm which is seated over the line and bolted to the body member using bolts, nuts, and washers. In other conventional examples, the electrical wire is secured to the insulator by the use of a vice-like arrangement that presses against the wire from the left and right side by tightening the nuts and bolts.
Electrical utility workers, or linemen, are generally not allowed to touch the insulator through which a charged wire passes. Instead, the lineman are required to utilize an insulated pole known as a “hot stick” or “switch stick” to protect them from electric shock and to provide physical separation from the insulator to reduce the chances of burns. Hot sticks are usually made of fiberglass and are made in variety of lengths, from a few feet up to forty feet in length. However, most hot sticks are typically six to ten feet in length.
While insulated hot sticks provide safe contact with energized equipment, their use presents a number of disadvantages in installing, tightening, removing, and loosening the typical conductor from an insulator. This operation requires the lineman to meticulously manipulate the hot stick in order to tighten or loosen the nuts and bolts of the typical clamping arrangement. Typically, said bolt is positioned parallel to the ground which makes it difficult to access the eyelet or bolt with a hot stick. This extensive and meticulous operation presents obvious safety hazards to the lineman and results in an inefficient and time consuming process for most electrical line crews.
The conventional electrical power line clamp presents other disadvantages. This includes the opportunity for parts, such as nuts and bolts, to be dropped during the installation or removal process. Rather than carrying a clamping apparatus that also serves as an insulator, the conventional arrangement also requires linemen to carry separate insulators and clamps for the installation and removal process. Moreover, because conventional electrical clamps are not universally adapted to secure electrical wires of various diameters, linemen are often required to carry a variety of clamp sizes for securing electrical wires of different sizes.
Some conventional clamping arrangements utilize a clamping device comprising a body member on which the line is placed and a clamping arm. The clamping arm is then seated over the line and bolted to the body member so they are hingebly connected. When the electrical wire is secured to the clamp in this typical arrangement, the electric wire runs parallel to the axis of the hinge that secures the clamping arm to the body member and also runs perpendicular to the clamping arm itself. Furthermore, when the electrical wire is secured to the clamp in the conventional arrangement, the electrical wire is equidistant from the axis of the hinge and the end of the clamping arm in the closed position such that a “symmetrical fulcrum” effect is utilized to secure the wire. However, in this conventional arrangement the symmetrical fulcrum effect and the parallel relationship between the electrical wire and the axis of the hinge do not provide a sufficient bearing force directly on the electrical wire to secure it in place. Herein, the term “axis” refer to an imaginary line about which rotation occurs (e.g., hinge axis 50) or the term axis can be a reference line used in defining one or more angles (examples include fixture axis 72 and longitudinal axis 78, described below).
Accordingly, there is a significant need for a clamping insulator that provides greater bearing force directly on the wire and can be easily manipulated using a hot stick. Such an improvement would further reduce certain hazards to linemen and limit the time required for installation and removal of the insulator. There is a need for an integrated insulator and clamp suitable for a variety of electrical wire diameters. Likewise, it is desirable for an insulated clamp to utilize an eyebolt, or a similar type of attachment, instead of nuts and bolts for securing the wire to the insulator. Along with other features and advantages outlined herein, clamping insulators within the scope of present embodiments meet these and other needs. In doing so, the inventive apparatuses provide greater bearing force directly on the wire, easier installation and removal of the insulator. Moreover, the use of an eyebolt or a similar type of attachment for securing the clamp in the closed position allows a lineman to easily manipulate the insulated clamp by the use of a hot stick, and a clamping apparatus with insulator adapted for accommodating a variety of wire diameters.